Erasing device



June 4, 1929. c. gREENE I I 1,715,912

ERASING DEVICE File'd Jan. 9, 1928 2 .1 Flyi- INVENTOR.

fawn/QM Patented June 4, 1929.

UNITED STATES PATENT OFFICE.

CURTIS GREENE, OF SAN DIEGO, CALIFORNIA.

ERASING- DEVICE.

My invention relates to an erasing device which is particularly intended for making erasures on paper in place on the platen of a typewriter but may be used for erasures in any manner and the objects of my invention are: first, to provide an erasing device operated by drawing over the surface to be erased a thin strip of paper or fabric, coated on the under side with a substance containing powdered abrasive matter while a pad, held rigidly in place in relation to the surface to be erased, is pressed against the upper side of the strip to erase IIltlKS, especially ink marks, difficult to remove by the ordinary methods of erasure, quickly and easily; sec- 0nd, to make said erasures in a manner which confines them to the parts only which are intended for erasure, leaving all surrounding marks unchanged; third, to provide a de-.

vice of this class which will distribute the pressure of the pad with the greatest practicable uniformity over its surface which comes in contact with the back of the aforesaid coated strip, to perform the erasure uniformly throughout, so that it may be made completely, without damaging any part of the surface by removing too much of it; fourth, to provide a device of this class that will perform the erasure in a manner which will reduce the amount of gritty debris which is formed by the present method of making erasures with rubber erasers containing abrasive matter, which without doubt causes deterioration in a typewriter if it enters its mechanism; fifth, to provide a new erasing strip member; sixth, to provide a novelly constructed erasing device, and seventh, to provide a device of this class which is very simple and economical to construct, easy ,to operate and which will not readily deteriorate or get out of order.

With these and other objects in view as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement of parts and portions as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters of reference thereon which form a part of this application in which:

Figure 1 is a side elevational view of my erasing device showing the handle fragmentarily; Fig. 2 is an end view of the device showing thehandle and erasing strip fragmentarily; Fig. 3 is a top view of the device with the handle and hinge bolt removed showing the erasing strip fragmentarily; Fig. 4 is an end view of the pad bar with the pads after removal from the device; Fig. 4 is a transverse cross section of the pad bar with the pads; Fig. 5 is a cross sectional view of one of the legs through 55 of Fig. 1; Fig. 6 is a sectional view of the same in a slightly modified form; Fig. 7 is a sectional view through 7 7 of Fig. 8 showing the device in another slightly modified form; Fig. 8 is a side elevational view of the device in said slightly modified form; Fig. 9 is an end view of same; Fig. 10 is a longitudinal sectional view of the device in another modified form; Fig. 11 is a perspective view of one side of the erasing strip and Fig. 12 is a perspective view of the opposite side thereof.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawings.

The device is entirely symmetrical with respect to a vertical plane through its transverse center line.

In the one form of my device shown in Figs. 1 to 5 and 11 to 12 inclusive, the pads l are of rectangular cross section and of different lengths, selected to give the greatest convenience in making erasures of different sizes. In the form intended for erasing typewritten printing, the pads are straight and of a uniform width, equal to the space, center to center, between the single-spaced typewritten lines, and their lengths are multiples of the space, center to center, between adja cent letters on the same line. They are made of a firm, resilient material, such pliable leather, felt or live rubber. In order to reduce friction to the minimum, if the face of the pad which touches the back of the erasing strip does not possess a naturally smooth, glossy surface, its surface is glazed by the application of a thin, flexible coating of varnishing material; or a thin, flexible sheet of glazed material may be cemented over it.

The pads 1, are cemented to the pad bar 2, preferably in shallow recesses in the same, with. the center of each pad midway between the ends of the pad bar, and with the longitudinal center line of the face of each pad parallel with and all equi-distant from the longitudinal center line, or axis, of the pad bar. The face of each pad is set at right angles to a radial line passing through its center from the axis of the pad bar.

The pad bar 2, is shouldered at each end, just beyond the ends of the longest pad, and the portion from each of said shoulders to its respective end is cylindrical, with a radius shorter than that or the central, portion of the pad bar. At its ends, the pad bar is cut off on planes at right angles to its sis. [it right angles to the plane of the outer face off each of the pads l, a shallow groove 3, with perpendicular sides is out across each of the flat ends of the pad bar 2, and passing through its axis.

The pad bar "frame a, is one piece oi? flat metal, bent dov-m at right angles at its ends, near the extremity oi each at which is cut a circular hole. Through these holes the cylindrical ends of the pad bar 2, pass, projecting for a short distance beyond and litting snugly, the ends of the pad bur frame resting againstthe shoulders on the pad bar. The pad bar is thus held by the pad bar frame, the only relative motion allowed be ing a rotary one around the axis of the pad bar. Tl e flat central portion of the pad bar frame is parallel to the axis of the pad bar, and clears the greatest projection on it and on the pads 1. Portions of the pad bar frame 4, projecting laterally on each side from its center, are bent up to right angles, and a circular hole is cut in each on the transverse center line of the device, both being equidistant from the plane of the top of said central portion of the pad bar frame.

The handle 5, is made of metal tubing, closed at its upper end, and having its lower end cut and bent to "form two parallel flat cars. In each of these cars is a round hole of the same diameter as those in the upward projecting portions of the pad bar frame, and so placed that the center line of the tubular portion of the handle will lie in a vertical plane passing through the centers of the two. Between these ears, where they join said tubular portion of the handle, other portions or" the lower end of the handle tul ing are flattened and bent at right angles across the open end of the handle, stiffening and partly closing it. The distance betwee. the flat portion of these cars is such that their outer faces will tit snugly between the inner faces of the upward projecting portions of the pad bar frame, in which position, and with all the holes in alinement, the bolt 6, of such diameter as to it snugly, is passed through the holes, forming a hinge. The fiat-nestled screw 7, threaded within a hole in the center of an end of the bolt 6, secures it in place. The handle 5 may be remover from the device by removing said screw 7, and witl'idrawing the bolt 6. The ends of the ears on the handle 5, are cut square and of such length to allow tree action in the hinge with the handle within about ten degrees from the vertical, but form a stop to further motion either way by striking the top of the central portion of the pad bar frame, This is to prevent the inconvenience of having to straighten out the handle from a doubled over position when starting to use the device. The object of the hinge is to prevent stronger pressure being applied on either end of the pad than on the other. In use, the handle must he held close enough to the vertical so that the hinge will function freely.

The spring 8, is of flat metal, attached rigidly to the top of the pad bar frame 4;, along its longitudinal center line, by the two screws 9, threaded to holes in the pad bar frame, one on each side of and both equidistant from the transverse center line of the device, and passing through oblong holes in the springo, on its longitudinal center line. These oblong holes allow longitudinal. a'ljustnient in the spring to render the spring pressure uniform at the two ends of the device.

The spring 8, is bent down at right angles just outside each end of the fiat central portion of the pad bar frame a, so to lie flat against. the Hat ends of the pad bar 2, pressin against both ends with considerable force. The shallow lugs 10, are torined integral with the spring 8, along its center line on the side which presses against each enu of the pad bar 2, and are of such cross section as to fit snugly into any of the grooves 3. The lugs 10 are best formed from the spring 8, itself, by punching through, and bending the metal inwardly, and should be slightly beveled to facilitate their entering the grooves 3, to hold the pad bar 2, rigidly from any rotary movement. i l hen an erasure is to be made, it the pad held in register by the lugs 10, is not ot the length desired, the right one is brought into register for making the erasure by first releasing the pad bar 2, by pressing the legs 11 at the ends of the spring apart with the thumb and finger of one hand, thus removing the lugs 10, from the grooves 3, and then turning the pad bar around slightly with the other hand. The outward pressure on the legs is then re leased, and the pad bar is turned further until the lugs snap into the proper grooves, holding the pad c esired in register.

The spring 8, is bent outward horizontally near the lower end of each of the lugs 10, and through a hole near each end of the spring and on its center line, one of the legs 1L, which are two in number, are bolted. Each leg has a shoe holder 12, made of thin, fiat metal, with a square top, in the middle of which is a round hole. The small bolt 13, with a flat, square head projects upwardly through said hole, the head being slightly smaller than the top of the shoe holder 12.

At each of its four sides the shoe holder is bent down at right angles, forming a shallow square tube in which the shoe 14, which is made of live rubber, fits snugly, pressing against the square end of the bolt 13. The lower corners of the shoe holder 12, are cut away a little, and the lower ends of the sides are pressed inwardly against the rubber shoe 1 1, crimping it securely in place. By bending said lower ends of the shoe holder sides outwardly to a vertical position both the shoe 14, and the bolt 13, may be removed, in case re placement of either is desired. A short length of the shoe 14: projects below the bottom of the shoe holder 12, and terminates in a flat end. The nut 15, is threaded to the bolt 13, and when in place, secures the leg 10 to the spring 8. The ends of the spring 8, beyond the legs 10, are bent diagonally downward and tapered to blunt points which terminate a short distance above the horizontal plane of the bottom of the shoes 14. These pointed ends afford a guide for placing the pad in true alinement over a line of typewritten printing, a portion of which is to be erased.

The points where the spring 8 is bent outward horizontally from the ends of the pad bar 2, are at such a Vertical distance from the plane of the face of the pad 1 which is in register, that said face is held a very short distance above the horizontal plane of the bottoms of the shoes 14.

To make an erasure, the proper pad being in register, it is first brought directly over the area to be erased, the shoes resting lightly on the surface on which the erasure is to be made. The erasing strip S which should be wider than the length of the pad, is then pushed for a portion of its length, with its side coated with abrasive matter down between the pad and the surface to be erased. The handle 5 is then pressed vertically downward with. one hand, which causes thehorizontal portions ofthe spring 8, outward from the screws 9, to bend upward, while the lugs 10 sl to in the grooves 3. This spring pressure causes the shoes 14 to grip the surface on which they rest firmly, keeping the pad 1 from slipping in relation to said surface, while it is pressed firmly against the back of the erasing strip, which is then drawn across said surface with the free hand, effecting the erasure, which is confined to the area of the surface di *ectly under the face of said pad.

A modified arrangement of the legs of this device is illustrated in Fig. 6 of the accompanying drawing.

In this form the legs which are four in number, two at each end of the device, instead of being bolted directly to the spring 8, are bolted to the ends of two cross bars 16,

throu h holes therein. The construction of said legs is exactly similar to that of the two legs heretofore described. cross bars 16 1s rectangular in cross sectlon Each of the two and has a notch cut at right angles across its lower side, midway between the legs, in which the spring 8 fits snugly. In the center of each of the cross bars 16 is a hole. Through each of said holes and holes in the spring 8, similarly placed to those heretofore described for bolting the legs to the spring, the screws 17, pass, having the nuts 18 threaded to them, bolting the crossbars 16, to the spring 8, at right an les therewith.

In the four leg construction as set forth above, in order that the device may function on the platen of a typewriter, the various parts must be so proportioned that the distance between the pad in register and the plane of the bottoms of the shoes will be sufficient to provide a space between the said pad and the surface on which the erasure is to be made, when used on the cylindrical surface of said platen.

A modified form of attaching the handle to the pad bar frame of this device is illustrated in Figs. 7, 8, and 9 of the accompanying drawings, in which a flat piece of spring steel takes the place of the hinge used in the construction heretofore set forth.

In this modified construction, the flat ears on the lower end of the handle 5 are of similar construction to those heretofore described, but are cut off square at their lower ends and are bent closer together, and lie flat on either side of one end of the spring connection 19, which is a short piece of fiat spring steel. In place of the single hole in each ear heretofore described, two holes are provided through each ear and through the spring connection between, and through these two holes the rivets 20 are driven, rigidly fastening the handle to the upper end of the spring connection.

The angle pieces 21, are two in number, made of flat metal the width of the spring connection 19, and bent at right angles on transverse lines near their centers. The vertical sections of the two are placed against opposite sides of the lower end of the spring connection 19, and the three pieces are riveted together by the two rivets 22, a T at the bottom of the spring connection being formed by the horizontal sections of the two angle pieces.

On the center line of the horizontal section of each of the angle pieces 21, a hole is bored, the two holes being equi-distant from the end of the spring connection 19, the distance between said holes being the same as the distance between the holes in the pad bar frame t, heretofore described, in which the two screws 9 are threaded. The screws 9 are made long enough to pass through the said holes in the angle pieces, and the oblong holes heretofore described in the spring 8, and into the aforesaid threaded holes in the pad bar frame, and serve to attach the said parts rigidly together, allowing, when loosened, the

longitudinal adjustment of the spring 8, heretofore set forth.

The projecting portions of the pad bar frame forming a part of the hinge in the construction heretofore described, are omitted in the spring connection. construction.

In the modified form shown in Fig. 10, the device is the same as the construction first set forth in all respects, with the following exceptions In this form the pad bar is omitted, and the pad 1 is cemented directly to the pad frame 23 (preferably in a shallow recess therein) which is in all respects similar to the pad bar frame of the construction first set forth, excepting that instead of being bent downward at ri 'ht an 'les at its ends it is cut off squarely at each end beyond the end of the pad.

The lugs 24 are four in number, two at each end of the pad frame 23, and are intogral with the same, being small projecting portions bent up vertically. They are so placed on each side of the spring 25, that they confine its motion relative to the pad frame 23 to a vertical one. Instead of the two screws 9 of the constructions heretofore set forth, one screw 26, only is used, and is threaded to a hole in the center of the pad frame, and passes through an oblong hole in the center of the spring 25, allowing longitudinal adjustment.

It will be noted that the erasing strips S may be made either of paper or cloth which is both tough and pliable and should be smooth and glossy on one side, the side which contacts the pad 1, while on the other side, which is the side which comes in contact with the surface to be erased, is coated witha substance containing powdered abrasive matter of a fine uniform texture and secured thereto so that it will not easily rub off, as shown best in Figs. 11 and 12.

It will be noted from the foregoing description, and with reference to the accompanying drawings, that my erasing device is made up of two separate parts, viz, the erasing strip and the holding mechanism, which co-operate to perform the erasure. It will also be noted that the abrasive matter on the under side of said erasing strip which performs the erasure when said strip is drawn by hand across the surface to be erased, will only perform said erasure with pressure applied to .the back of said strip, and that, said strip being thin and flexible, if said pressure is localized over a liniited area of the surface to be erased, the erasure will not extend appreciably beyond said limiter area under pressure. The function of the aforesaid holding mechanism is to bring such pressure over a selected limited area of the paper intended for erasure by means of its pad which is held in constant register therewith, the rubber shod legs of said holding mechanism preventing same from slipping onsaid paper, and the face of said pad, being glossy, allowing the erasing strip with its glossy back to slip freely between said pad and said paper while performing the erasure under pressure.

The revoluble pad bar of the construction hereinbefore first set forth, with several pads of different shapes and sizes, each pad being attached to a different face of said bar, affords a means of selecting a pad. best suited to the shape and size of the erasure to be made, said paid when selected being brought into fixed register to function in said holding mechanism in a manner hereinbefore described, before the erasure is started. The modified form of the holding mechanism hereinbefore set forth, which said form has no revoluble pad bar, and but one pad, performs erasure in co-operation with the erasing strip in a manner exactly similar to the holding mechanism first set forth, excepting that no selection of different shapes and sizes of erasure is afforded.

With the proper pad in register for erasure, the holding mechanism is grasped by its handle by the person making the erasure, and placed lightly on the paper on which the erasure is to be made, with said pad directly over the area intended for erasure. lVith the free hand said person then slips the erasing strip fora portion of its length and with its abrasive coated side down, through the clear space between said pad and said paper to be erased. With the same hand as at first still grasping the handle of the holding mechanism, said person performing the e asure then presses vertically downward, maintaining said handle in a perfectly upright position, while with the other hand still grasping the erasing strip he draws same across the paper to be erased, the abrasive removing a thin layer from the surface of said paper directly under the face of the pad and performing the erasure. After the erasing strip is pulled completely through under pressure, as above set forth, the holdin mechanism is tilted slightly with. two rubber shoes of same retaining their original positions on said paper, and there sult of the said operation is inspected. If the erasure has not leen completely performed, the holding mechanism is tilted back to its upright position, the erasing strip is again slipped between the pad and paper and the erasing operation is repeated.

Though I have shown and described. a particular construction, combination and arrangementof parts and portions and several modifications thereof, I do notwish .to be limited to this particular construction, combination and arrangement nor to the modifications but desire to include in'the scope of my invention the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what- I claim as new and desire to secure by Letters Patent, is:

1. In an erasing device, resilient supports adapted to engage the paper to be erased, a pad resiliently supported thereon adapted to be depressed nearly into engagement with the paper to be erased, and an erasing strip interposed between said pad and said paper.

2. In an erasing device, resilient supports adapted to engage the paper to be erased, a pad resiliently supported thereon adapted to be depressed nearly into engagement with the paper to be erased, an erasing strip interposed transversely between'said pad and said paper to be erased and a handle member resiliently connected with said pad.

3. In an erasing device, resilient supports adapted to engage the paper to be erased, a pad resiliently supported thereon adapted to be depressed nearly into engagement with the paper to be erased, an erasing strip inter posed transversely between said pad and said paper to be erased, and a handle member pivotally connected to said support.

4. In an erasing device, a plurality of resilient supporting members, a plate mounted thereon, a pad mounted on said plate between said resilient supports, and an erasing strip engageable by said pad.

5. In an erasing device, a plurality of resilient supporting members, a resilient plate mounted thereon, a pad mounted on said resilient plate between said resilient supports, an erasing strip interposed between one of per to be erased and a handle member resiliently connected with said erasing pad support.

7. In an erasing device, a strip member providedwith fine abrasive material on its under side and smooth on its upper side, and resilient means by which the upper smooth side of said strip is engaged.

8. In an erasing device, a strip member provided with line abrasive material on its under side, and a resilient supporting means engaging the upper side of said strip.

9. In an erasing device, spaced resilient supports, a resilient member supported thereon, a plurality of variable length pads revolubly mounted thereon, an erasing strip interposed between one of said pads and the paper to be erased and a handle member resiliently connected with said erasing pad support and means in connection with said resilient memher for engaging and presenting the revolution of said pads, when in operating position.

In testimony whereof, I have hereunto set my hand at San Diego, California, this 27th day of December, 1927.

. CURTIS GREENE. 

